The invention relates to a knitting machine. The present invention relates generally to a knitting machine having a bed for knitting implements and a cam arrangement for controlling the knitting implements.
Knitting machines can be provided essentially with three kinds of cam portions.
The cam portions of a first kind are those which are permanently or easily interchangeably mounted to their carriers. Those cam portions are generally mounted on the front side of the carrier which faces the bed for the knitting implements and have either a closed cam track in the form of a groove which is milled into the front side thereof or define a cam track formed from a plurality of cam portions, with the outside contour of the cam portions. Hybrid forms thereof are also known. In such arrangements the holding means comprise fixing means and primarily screwthreaded bores provided in the front side of the carrier and having the axes which extend in the direction of the bed. The bores receive fixing screws which pass through the cam portions. In that way the cam portions are rigidly fixed to the carrier and after fitting thereof are held at a predetermined spacing from the bed, that spacing being referred to as the cam play. Besides those fixing means, such an arrangement generally has additional positioning elements disposed on the carriers and cam portions and formed as pins, bores or the like which fix the position of the cam portions in all directions extending perpendicularly to the axis or operative direction of the fixing means (for example U.S. Pat. No. 4,037,434, German patent specifications Nos. 25 44 197 and 27 46 725, German laid-open application (DE-OS) No. 28 07 206 and German utility model No. 80 28 544). Suitable fixing screws are used when the arrangement has cam portions of a parallelepipedic or cubic configuration a plurality of cam tracks and can be secured to the carriers in different positions (German patent specification No. 23 66 173 and German published specification (DE-AS) No. 22 42 169). It is also known that a plurality of cam portions may be secured to a carrier by means of a single fixing screw (EU 0 314 062) in order to speed up the replacement operation. Instead of using fixing screws, the cam portions may also finally be secured to the carriers by means of elements which have a positive engagement effect and which serve for faster replacement (German patent specification No. 1 938 891), or by glueing, pressing, soldering, brazing or the like (German utility models Nos. 79 10 547 and 79 10 610).
The cam portions of the second kind are mounted on parts of the carrier which are displaceable parallel to the bed of the knitting implements, in order for example to permit adjustment of the stitch length or to perform other functions related to the knitting procedure. In that situation the cam portions are also secured to the movable part of the carrier by fixing means (U.S. Pat. No. 350,794, German laid-open application (DE-OS) No. 22 45 416 and German patent specifications Nos. 30 02 540 and 31 04 298) and are possibly fixed in position by additional positioning elements. In that arrangement the cam play is generally kept constant by the movable part disposed in a positive-engagement guide which extends parallel to the bed.
The cam portions of the third kind which however are of no interest from the point of view of the purposes of the present invention, are fixed to a part of the carrier which is displaceable in the direction of the bed for the knitting implements, in order to permit faster replacement of the cam portions or to control the action of the cam portions on the knitting implements by moving the cam portions forwards and backwards (German published specifications (DE-AS) Nos. 15 85 412 and 20 53 856 and DE-OS No. 25 56 374). In that arrangement fixing of the cam portions to the movable parts of the carrier is indispensible as otherwise it would not be possible to provide the intended function. In addition the forward movement in the bed direction is generally additionally limited by abutments which have a positive engagement action, or the like.
Since the beginning of the knitting machine art, the cam portions of the first and second kinds which are of interest and the cam portions of the third kind, have been fixedly and immovably secured by fixing screws or other fixing means to the carriers which in turn are rigidly or movably mounted to the knitting machine. That fixing action is provided in spite of the generally known fact that, in relation to manufacture, fitment and possibly replacement of the cam portions of the first and second kinds, that fixing effect involves a considerable contribution to the production and assembly costs. In the case of high-system circular knitting machines and when using very small cam portions, there is very little space available for arranging the fixing screws and positioning elements and the above-mentioned means for speeding up the fitting or replacement operation (German patent specification No. 19 38 891, DE-OS No. 37 33 811 and EU 0 314 062) cannot always be used, for various reasons, in part involve even higher production costs, or give rise to problems in regard to the tolerances to be maintained.